La Niña finally at an end

The climate monitoring services have just announced the end of the La Niña phenomenon, ongoing since 2020. While it is a recurrent climate phenomenon, which appears every three to four years, we should note the peculiarity of the current one in terms of its duration, over three consecutive seasons: 2020-2021, 2021-2022 and 2022-2023. We need to go back to 1999-2001 to find an episode of similar duration.   

This phenomenon contributes to oceanic and atmospheric cooling of the coasts of South America, with knock-on climate impacts worldwide. Generally, La Niña results in a cooler December to February period on the coasts of Peru and Ecuador, more abundant abundant from North-East Brazil to Colombia, higher temperatures in the Gulf of Mexico zone (and consequently the cyclone season more active), and indeed cooler temperatures in West Africa. The 2020-2021 episode, of middling intensity, was marked by a highly intense cyclone season (Eta and Iota), as well as by cold climate conditions which delayed the progression of the Colombian and Ecuadorian banana supplies. The 2021-2022 season was marked by record rainfall in Colombia and delayed Ecuadorian production. The impacts continued in 2022-2023, though they have eased off since February.

While a return to normal is expected from spring, the models are already indicating a high probability (60 %) of El Niño appearing by the end of 2023. This phenomenon, which unlike La Niña contributes to warming the waters of the South Pacific, reaches maximum intensity around Christmas: dry conditions develop in Indonesia and Australia, tropical storms and hurricanes appear much further east than usual, while the coasts of Peru and Ecuador experience exceptional precipitation, causing floods and landslides.